1/* @(#)e_scalb.c 5.1 93/09/24 */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13#if defined(LIBM_SCCS) && !defined(lint)
14static char rcsid[] = "$NetBSD: e_scalb.c,v 1.6 1995/05/10 20:46:09 jtc Exp $";
15#endif
16
17/*
18 * __ieee754_scalb(x, fn) is provide for
19 * passing various standard test suite. One
20 * should use scalbn() instead.
21 */
22
23#include <fenv.h>
24#include "math.h"
25#include "math_private.h"
26
27#ifdef _SCALB_INT
28#ifdef __STDC__
29	double __ieee754_scalb(double x, int fn)
30#else
31	double __ieee754_scalb(x,fn)
32	double x; int fn;
33#endif
34#else
35#ifdef __STDC__
36	double __ieee754_scalb(double x, double fn)
37#else
38	double __ieee754_scalb(x,fn)
39	double x, fn;
40#endif
41#endif
42{
43#ifdef _SCALB_INT
44	return __scalbn(x,fn);
45#else
46	if (__isnan(x)||__isnan(fn)) return x*fn;
47	if (!__finite(fn)) {
48	    if(fn>0.0) return x*fn;
49	    else if (x == 0)
50	      return x;
51	    else if (!__finite (x))
52	      {
53# ifdef FE_INVALID
54		feraiseexcept (FE_INVALID);
55# endif
56		return __nan ("");
57	      }
58	    else       return x/(-fn);
59	}
60	if (__rint(fn)!=fn)
61	  {
62# ifdef FE_INVALID
63	    feraiseexcept (FE_INVALID);
64# endif
65	    return __nan ("");
66	  }
67	if ( fn > 65000.0) return __scalbn(x, 65000);
68	if (-fn > 65000.0) return __scalbn(x,-65000);
69	return __scalbn(x,(int)fn);
70#endif
71}
72